Magnetically tuned, robust and efficient filtering system for spatially multimode quantum memory in warm atomic vapors.

Warm atomic vapor quantum memories are simple and robust, yet suffer from a number of parasitic processes which produce excess noise. For operating in a single-photon regime precise filtering of the output light is essential. Here, we report a combination of magnetically tuned absorption and Faraday filters, both light-direction insensitive, which stop the driving lasers and attenuate spurious fluorescence and four-wave mixing while transmitting narrowband Stokes and anti-Stokes photons generated in write-in and readout processes. We characterize both filters with respect to adjustable working parameters. We demonstrate a significant increase in the signal-to-noise ratio upon applying the filters seen qualitatively in measurements of correlation between the Raman scattered photons.

Quantum noise limited and entanglement-assisted magnetometry.

We study experimentally the fundamental limits of sensitivity of an atomic radio-frequency magnetometer. First, we apply an optimal sequence of state preparation, evolution, and the backaction evading measurement to achieve a nearly projection noise limited sensitivity. We furthermore experimentally demonstrate that Einstein-Podolsky-Rosen entanglement of atoms generated by a measurement enhances the sensitivity to pulsed magnetic fields. We demonstrate this quantum limited sensing in a magnetometer utilizing a truly macroscopic ensemble of 1.5x10(12) atoms which allows us to achieve subfemtotesla/square root(Hz) sensitivity.

High quality anti-relaxation coating material for alkali atom vapor cells.

We present an experimental investigation of alkali atom vapor cells coated with a high quality anti-relaxation coating material based on alkenes. The prepared cells with single compound alkene based coating showed the longest spin relaxation times which have been measured up to now with room temperature vapor cells. Suggestions are made that chemical binding of a cesium atom and an alkene molecule by attack to the C = C bond plays a crucial role in such improvement of anti-relaxation coating quality.

Generation of two-mode squeezed and entangled light in a single temporal and spatial mode.

We analyse a novel squeezing and entangling mechanism which is due to correlated Stokes and anti-Stokes photon forward scattering in a multi-level atom vapour. We develop a full quantum model for an alkali atomic vapour including quantized collective atomic states which predicts high degree of squeezing for attainable experimental conditions. Following the proposal we present an experimental demonstration of 3.5 dB pulsed frequency nondegenerate squeezed (quadrature entangled) state of light using room temperature caesium vapour. The source is very robust and requires only a few milliwatts of laser power. The squeezed state is generated in the same spatial mode as the local oscillator and in a single temporal mode. The two entangled modes are separated by twice the Zeeman frequency of the vapour which can be widely tuned. The narrow-band squeezed light generated near an atomic resonance can be directly used for atom-based quantum information protocols. Its single temporal mode characteristics make it a promising resource for quantum information processing.

Optimal quantum phase estimation.

By using a systematic optimization approach, we determine quantum states of light with definite photon number leading to the best possible precision in optical two-mode interferometry. Our treatment takes into account the experimentally relevant situation of photon losses. Our results thus reveal the benchmark for precision in optical interferometry. Although this boundary is generally worse than the Heisenberg limit, we show that the obtained precision beats the standard quantum limit, thus leading to a significant improvement compared to classical interferometers. We furthermore discuss alternative states and strategies to the optimized states which are easier to generate at the cost of only slightly lower precision.

Broadband noncollinear optical parametric amplifier using a single crystal.

A noncollinear optical parametric amplifier in which blue pump pulse generation as well as parametric amplification takes place in the same nonlinear crystal is presented. Broadband spectra tunable throughout over 100 nm in the visible were generated in a simple setup. The green output pulses were compressed to 65 fs, and efficiency (IR-to-visible) of 1.8% was achieved.

Piezo-driven deformable mirror for femtosecond pulse shaping.

We have developed a deformable, gold-coated mirror based on piezoelectric actuators with 15-micros response time. With 20 independent channels we were able to compress 72-fs pulses from a Ti:sapphire oscillator down to 45 fs in a 4f zero-dispersion compressor arrangement. Spectral interference was used to measure the mirror performance, while the spectral phase interferometry for direct electric field reconstruction (SPIDER) technique was used for the laser pulse characterization.

[Surgical treatment of lateral extraforaminal lumbar disc herniation]. / Leczenie operacyjne bocznych zewnatrzkanalowych przepuklin jadra miazdzystego w odcinku ledzwiowym kregoslupa.

Extraforaminal lumbar disc herniations with spinal nerve compression are a well-recognised entity. The diagnosis is difficult although the clinical syndrome is quite characteristic. Myelography fails to disclose these lesions, while CT, MRI or discography are helpful. The best approach to the extreme-lateral lumbar disc herniation is microsurgical decompression of the spinal nerve via the intertransverse muscle, ligament and fascia. With this approach, there is no facet destruction and satisfactory nerve root decompression is safe and effective in relieving radicular pain.

[MRI of traumatic superficial temporal artery aneurysm. Case report]. / Obraz MRI urazowego tetniaka powierzchownej tetnicy skroniowej. Opis przypadku.

A case of 14-years-old girl with superficial temporal artery aneurysm is presented. She sustained head injury six weeks before the first symptom. Presence of the recent blunt trauma in confrontation with MRI lead to establishing of the final diagnosis. It must be considered in the differential diagnosis of masses located in the temporal fossa. Surgical resection of the involved segment of the vessel is indicated in the cases without the need of reconstruction. The result of treatment in our case was excellent and all symptoms have resolved. The aneurysmal character of the lesion was confirmed by histopathological examination.

[Repeated operations for recurrent lumbar disc herniations]. / Wielokrotne operacje przepuklin jadra miazdzystego w odcinku ledzwiowym.

A study of 73 patients who underwent reoperation for persistent or new complaints following initial lumbar discectomy is presented. 32 patients showed true recurrence of disc herniation (6 on the contralateral side) and 41 at a different level. 14 patients needed 3rd operation. Final results were evaluated using the Functional Economic Rating Scale elaborated by Prolo. Mean score for group operated on twice was 8.1 according to Prolo and 7.1 for group operated on 3 times.

[Epidural gas aggregation in the course of gaseous degeneration of lumbar intervertebral disk as a cause of foot paresis]. / Obecnosc zewnatrzoponowego gazu sródkanalowo w przebiegu gazowego zwyrodnienia jadra miazdzystego w odcinku ledzwiowym jako domniemana przyczyna niedowladu prostowników stopy.

The finding of gas within the vertebral disc space ("vacuum phenomenon") is relatively common. Degenerative spine disease, gaseous degeneration of the intervertebral disc, and epidural gas were disclosed on imaging study. The epidural gas could be attributed to gaseous disc degeneration. The nerve root in presented patient was compressed by epidural gas. Following surgery the clinical syndrome including foot drop has thoroughly resolved.

Meningiomas of the lateral ventricles of the brain in children.

Meningiomas of the lateral ventricles of the brain are rare tumours, accounting for approximately 0.5-5% of all intracranial meningiomas. Their natural history and symptomatology and the possibilities of early diagnosis are presented. The intraventricular location of the slow-growing benign mass provides a compensatory mechanism in the form of reserve space, which contributes to the delay in clinical demonstration of symptoms and signs. This makes the choice of diagnostic procedure an essential problem. CT and MRI are useful in detecting these masses, and magnetic resonance angiography (MRA) has also proved to be of great value in demonstrating the vascular supply of the tumour. This paper deals with two cases. In case 1 CT, MRI and MRA and in case 2 CT examination proved to be very useful. The tumours were removed by a transcortical approach in the posterior area.

Posterior fossa tumors in children--indications for ventricular drainage and for V-P shunting.

A clinical analysis of 95 patients with posterior fossa tumors treated in the Department of Neurosurgery of the Medical University in Gdansk over a period of 16 years (1979-1995) is presented. The following preoperative factors were studied: localization, size and suspected type of tumor, size of the ventricular system, and presence or absence of the "halo" symptom. The indications for ventricular drainage (Fisher) versus V-P shunting as a preliminary treatment are discussed. Finally, the advantages of each of these procedures are emphasized.

Effect of chronic vanadium administration in drinking water to rats.

Two-month old Wistar rats of both sexes received, as sole drinking liquid, an aqueous solution of ammonium metavanadate (AMV) at a concentration of 0.01 or 0.05 mg V cm-3 (0.2 or 1.0 mM) for a period of 4 weeks. It was calculated that the animals took up doses of 1.5 and 5-6 mg V kg body weight-1 24 h-1, respectively. Food and AMV solution consumption in the experimental group was similar to food and water consumption in the control group. A statistically significant decrease of consumption of AMV solution at a concentration of 0.05 mg V cm-3 was noted only in males. Hematological examination demonstrated a decrease in the erythrocyte count, hemoglobin level and hematocrit index. This decrease in the erythrocyte count was associated with an increased percentage of reticulocytes in the peripheral blood of the animals drinking the solution with a higher vanadium content. Biochemical analyses demonstrated a decrease of L-ascorbic acid levels in the plasma and erythrocytes of animals drinking the AMV solutions. A distinct tendency for the malonyldialdehyde level to increase in the blood was also observed. Among the enzymes examined in the erythrocytes (catalase, glucose-6-phosphate dehydrogenase, lactate dehydrogenase and delta-aminolevulinic acid dehydratase [ALA-D]) only ALA-D activity was depressed.

Combined effect of vanadium and zinc on certain selected haematological indices in rats.

1. Two-month-old Wistar rats of both sexes received, as sole drinking liquid, an aqueous solution of ammonium metavanadate (AMV) and zinc chloride (ZC) at concentrations of 0.30 mg V/cm3 and 0.12 mg Zn/cm3 respectively, for a period of 4 weeks. 2. The reference groups received for drinking at this time: water, AMV or ZC solutions at the same concentration. 3. In all groups of animals there was a statistically significant decrease in the uptake of food, AMV or ZC, as well AMV-ZC solutions, as compared with the food and water taken up by the control group. 4. In the group of animals receiving AMV or AMV-ZC solution for drinking the body weight increment diminished significantly. 5. In the animals drinking the AMV-ZC solution a statistically significant decrease in the erythrocyte count and haemoglobin level in the peripheral blood were recorded, similar to the groups drinking AMV or ZC solution. 6. In rats drinking aqueous AMV or ZC solutions and in females receiving AMV-ZC solution the percentage of reticulocytes and polychromatophilic erythrocytes increased, moreover, in the peripheral blood. It was not, however, associated with marked percentage changes in the composition of the bone marrow cells.

Haematological effects of vanadium on living organisms.

Although vanadium has been of great interest for many researchers over a number of years, its biochemical and physiological role is not yet fully clear. There are many papers describing the haematological consequences of its excess in living organisms and most of their data are quoted in this mini-review. The authors of these papers used various laboratory animals, different vanadium compounds, frequently different routes of administration and duration of intoxication. Hence a checklist and comparison of the results are rather difficult. Vanadium reduces the deformability of erythrocytes, and such cells are rather frequently retained in the reticuloendothelial system of the spleen and eliminated faster from the blood stream (Kogawa et al., 1976). Vanadium produces peroxidative changes in the erythrocyte membrane, this leading to haemolysis. Therefore, the depressed erythrocyte count in animals intoxicated with vanadium may be the consequence of both the haemolytic action of vanadium and the shortened time of survival of erythrocytes. Changes of the haem precursor level in blood serum and urine observed in humans exposed occupationally to vanadium suggest an influence of this element on haem synthesis. This problem requires, however, further studies and observations. Changes occurring under the influence of vanadium on the leukocyte system of animals suggest the influence of this element on the resistance of the organism, but the mechanism of the action of vanadium still requires elucidation.(ABSTRACT TRUNCATED AT 250 WORDS)

Haematological results of vanadium intoxication in Wistar rats.

1. Two-month-old rats of the Wistar strain of both sexes received, as sole drinking liquid, an aqueous solution of ammonium metavanadate (AMV) of 0.15 mg V/cm3 concentration for a period of 4 weeks. 2. A small decrease in the amount of food consumed and a significant reduction of the water AMV solution drunk were observed, as compared with the food and water taken up by the control group. 3. In the peripheral blood a significant decrease in the erythrocyte count and haemoglobin level and increased percentage of reticulocytes and polychromatophilic erythrocytes were noted. 4. No changes in the activity of lactate dehydrogenase (LDH) and glucose-6-phosphate dehydrogenase (G-6PD) were found in the erythrocytes of the animals tested. 5. The increase in the neutrophilic granulocyte and lymphocyte count was significant. 6. An inhibitory influence of vanadium on the phagocytic activity of granulocytes was observed.

[Evaluation of the results of the treatment of cerebral hematoma in relation to its volume using the "best fit" method]. / Próba oceny wyników leczenia krwiaków sródmózgowych w zaleznosci od objetosci obliczanej metoda "najlepszego dopasowania".

A method is described in which the volumes of intracerebral haematomas were retrospectively measured by a method of best-fitting circles, in 173 consecutive patients. 173 patients were operated on and 41 were treated conservatively. Prognosis in supratentorial haematomas of the volume up to 65 ml is better by 20% when they are treated conservatively. It seems that surgical treatment should be reserved for patients with haematomas over 65 ml presenting progressive deterioration of neurological condition. On the other hand, patients with infratentorial haematoma over 14 ml of volume should be operated on as quickly as possible.

Significance of reduced food and water consumption in rats intoxicated with vanadium.

1. Male Wistar rats were given, for four weeks, a limited amount of food, or the amount of food and water equal to that consumed by rats drinking solely an aqueous solution of ammonium metavanadate instead of water (AMV) of 0.3 mg V/cm3 concentration. 2. In rats with limited access to food but free access to water, a significant decrease of body weight increment was observed, together with an increase of the haemoglobin level and a decrease in the percentage of reticulocytes and polychromatophilic erythrocytes in the peripheral blood. 3. In the rats which did not receive food and water ad libitum a significant decrease of the body weight increment and an increase of the haemoglobin level were noted. 4. In animals drinking the aqueous AMV solution instead of water the body weight increment diminished significantly, and so did the erythrocyte count and haemoglobin level, whereas the percentage of reticulocytes and polychromatophilic erythrocytes increased in the peripheral blood.

Some selected haematological indices in Wistar rats in the vanadium-ethanol interaction.

1. Wistar rats of both sexes daily received an ethanol solution of ammonium metavanadate (AMV) of 0.3 mg V/cm3 5% ethanol concentration as sole drinking liquid, for a period of 4 weeks. 2. The reference groups received for drinking aqueous AMV solution, or 5% ethanol, or water. 3. In animals drinking both water and ethanol AMV solution a decrease in the erythrocyte count and haemoglobin level was noted together with an increase of the percentage of reticulocytes and polychromatophilic erythrocytes in the peripheral blood. 4. A small rise of the percentage of polychromatophilic and orthochromatic erythroblasts was at the same time noted in the bone marrow of animals receiving ethanol AMV solution. 5. In the group of animals drinking 5% ethanol a fall of the erythrocyte count was observed and a rise of the leukocyte count, particularly of lymphocytes. 6. Substitution of water by 5% ethanol solution as solvent for AMV did not have any distinct influence on the toxicity of the tested compound.